When signals are received, transmitted, or processed, they are often represented as electromagnetic waveforms. Many products are available for processing such signals, and it is common practice to transform between domains of frequency and time, or frequency and space, to achieve desired results. In particular, an electrocardiograph monitors electrical signals produced by a beating heart. Other products monitor light waves transmitted in an optical fiber and others monitor the power transmitted in a wire.
Monitors may also compare the received waveform signals with defined waveforms and produce a desired result when an abnormal waveform is detected. For example, an implanted cardiac pacer may produce a stimulating pulse when it detects a heart arrhythmia.
It will be appreciated that a waveform signal monitor that does not function properly may cause serious consequences. Therefore, a variety of signal generator products such as arbitrary waveform generators and simulators have been developed to test waveform signal monitors by generating waveform signals that simulate real-world signals that are expected to be monitored.
A typical waveform signal generator may contain several digitized waveforms in non-volatile memory. Upon a request, a digitized waveform is recalled from memory and processed through a digital/analog convertor. The resulting analog, waveform signal then is sent to the monitor that is being tested. The monitor's response to a known waveform or series of waveforms can then be observed.
The specific waveforms will vary according to the anticipated use of the waveform generator or simulator. For example, a simulator for use with a cardiac pacer or electrocardiograph may contain an R-wave and several common arrhythmia waveforms. A simulator for use with an optical fiber transmission monitor may contain backscatter waveforms associated with several common imperfections in the fiber.
Modern Signal Generators typically contain a variety of waveform shapes and have access to many more from remote sources. Regardless of the method by which digitized waveforms are provided, there remains the problem of finding, defining, or otherwise creating shapes for the waveforms to be provided. However, it seems that there is no systemized method by which new, uncommon, or previously non-existent waveforms are organized and published for waveform signal generators.